Biodegradable sheet

Abstract

Disclosed is a biodegradable sheet comprising at least one layer which is a direct contact layer, intended to successfully contact materials, such as liquids, while maintaining the mechanical properties of the sheet and to extend the biodegradable sheet shelf life. The direct contact layer may comprise a hydrophobic polymer selected from poly(epsilon-caprolactone) (PCL) polyhydroxybutyrate (PHB), Polydioxanone (PDO) polyglycolic acid (PGA), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), poly lactic acid (PLA), polybutylene adipate terphtalate (PBAT), polyhydroxyalkanoates (PHA), such as polyhydroxybutyrates (PHB), polyhydroxyvalerates (PHV), and polyhydroxybutyrate-hydroxyvalerate copolymers (PHBV) or any mixture thereof. The biodegradable sheet may further comprise surface treated nanoclay particles, PVOH grafted with a crosslinker and PBS or PBSA The first hydrophobic polymer is present in said at least one layer in an amount of about 30% w/w.

What is claimed is: 
     
       1. A three layered biodegradable sheet, comprising a first layer, a second layer and a third layer,
 wherein at least one of said first layer or said third layer comprises about 100% w/w PBS or about 100% w/w PBSA; 
 wherein said second layer comprises a first hydrophobic polymer selected from the group consisting of poly(epsilon-caprolactone) (PCL), a polyhydroxyalkanoate (PHA) and a mixture thereof, and a second hydrophobic polymer selected from the group consisting of polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), poly lactic acid (PLA), polybutylene adipate terephthalate (PBAT), polydioxanone (PDO), polyglycolic acid (PGA) and any mixture thereof, 
 wherein said first hydrophobic polymer is present in said second layer in an amount of about 30% w/w; and 
 wherein said second layer is situated between said first layer and said third layer. 
 
     
     
       2. The biodegradable sheet according to  claim 1 , wherein the first hydrophobic polymer is PCL. 
     
     
       3. The biodegradable sheet of  claim 1 , wherein said second hydrophobic polymer is selected from the group consisting of PLA, PBS, PBSA and PBAT. 
     
     
       4. The biodegradable sheet of  claim 1 , wherein said second hydrophobic polymer comprises PLA. 
     
     
       5. The biodegradable sheet of  claim 1 , wherein said first hydrophobic polymer comprises PCL and said second hydrophobic polymer comprises PLA. 
     
     
       6. The biodegradable sheet of  claim 1 , wherein said second hydrophobic polymer is a mixture of PBS and PBSA, a mixture of PBS and PLA, a mixture of PBSA and PLA or a mixture of PBAT and PLA. 
     
     
       7. The biodegradable sheet of  claim 1 , wherein at least one of said first layer and said third layer comprises about 100% w/w PBSA. 
     
     
       8. The biodegradable sheet of  claim 7 , wherein each of said first layer and said third layer comprises about 100% w/w PBSA. 
     
     
       9. The biodegradable sheet of  claim 8 , wherein said first hydrophobic polymer comprises PCL and said second hydrophobic polymer comprises PLA. 
     
     
       10. The biodegradable sheet of  claim 1 , wherein at least one of said first layer and said third layer comprises about 100% w/w PBS. 
     
     
       11. The biodegradable sheet of  claim 10 , wherein each of said first layer and said third layer comprises about 100% w/w PBS.